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Publication numberUS6969907 B2
Publication typeGrant
Application numberUS 10/262,865
Publication dateNov 29, 2005
Filing dateOct 3, 2002
Priority dateDec 21, 1999
Fee statusPaid
Also published asDE60043767D1, EP1111677A2, EP1111677A3, EP1111677B1, US20010022395, US20030025197
Publication number10262865, 262865, US 6969907 B2, US 6969907B2, US-B2-6969907, US6969907 B2, US6969907B2
InventorsMakoto Imai, Naoki Ogawa, Yuji Yagi, Takashi Kojima, Yasushi Yamada
Original AssigneeToyota Jidosha Kabushiki Kaisha
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Cooling structure for multichip module
US 6969907 B2
Abstract
A first electronic device, a second electronic device which generates less heat than the first electric device, and an electrode are connected by a heat leveling plate formed of an electrically conductive material having high thermal conductivity. A heat radiation plate is provided below an insulated substrate to which the first and second electronic devices are mounted. The second electronic device is cooled by a heat radiation path which extends through the insulated substrate and the heat radiation plate and a heat radiation path which extends through the second electronic device and the electrode to the heat radiation plate. The first and the second electronic device have substantially the same temperature due to heat radiation through the heat leveling plate. As a result, cooling effect of the electronic devices can be enhanced.
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Claims(19)
1. A cooling structure for a multichip module having a plurality of electronic devices which generate different amounts of heat relative to each other, the cooling structure comprising:
a first member which forms a first face of the multichip module and which transmits heat generated by the electronic devices to the outside of the module; and
a second member which forms a second face of the multichip module that is different from the first face, which is in contact with the electronic devices and which does not contact the first member, and which has thermal conductivity,
wherein the plurality of electronic devices includes at least one low heat device comprising a diode and at least one high heat device selected from the group consisting of an insulated gate bipolar transistor, a metal-oxide semiconductor and a power transistor, and
heat generated from the high heat device flows to the first member through the low heat device and the second member.
2. A cooling structure according to claim 1, wherein the first member transmits heat generated by the electronic devices to a cooling medium.
3. A cooling structure according to claim 2, wherein the cooling medium includes air and water.
4. A cooling structure according to claim 1, wherein the second member has electrical conductivity and is electrically in contact with the electronic devices.
5. A cooling structure according to claim 2, wherein the second member comprises an insulating member and a wiring pattern which is electrically in contact with the electronic devices.
6. A cooling structure according to claim 1, further comprising a third member that supports the electronic devices, wherein a coefficient of thermal expansion of the second member and that of the third member are in a predetermined range at steady driving state of the multichip module.
7. A cooling structure according to claim 6, wherein the coefficient of thermal expansion of the second member is substantially the same as that of the third member.
8. A cooling structure according to claim 6, wherein the third member is a substrate on which the electric devices are arranged.
9. A cooling structure according to claim 1, wherein a coefficient of thermal expansion of the first member and that of the second member are in a predetermined range at steady driving state of the multichip module.
10. A cooling structure according to claim 4, further comprising a third member that supports the electronic devices, wherein a coefficient of thermal expansion of the second member and that of the third member are in a predetermined range at steady driving state of the multichip module.
11. A cooling structure according to claim 10, wherein the coefficient of thermal expansion of the second member is substantially the same as that of the third member.
12. A cooling structure according to claim 10, wherein the third member is a substrate on which the electric devices are arranged.
13. A cooling structure according to claim 4, wherein a coefficient of thermal expansion of the first member and that of the second member are in a predetermined range at steady driving state of e multichip module.
14. A cooling structure according to claim 13, further comprising a third member that supports the electronic devices, wherein a coefficient of thermal expansion of the second member and that of the third member are in a predetermined range at steady driving state of the multichip module.
15. A cooling structure according to claim 12, wherein the coefficient of thermal expansion of the second member is substantially the same as that of the third member.
16. A cooling structure according to claim 1, wherein the first and second members are so located to sandwich the electronic devices.
17. A cooling structure according to claim 2, wherein the second member has electrical conductivity and is electrically in contact with the electronic devices.
18. A cooling structure according to claim 2, wherein the second member comprises an insulating member and a wiring pattern which is electrically in contact with the electronic devices.
19. A cooling structure according to claim 14, wherein the third member is a substrate on which the electrical devices are arranged.
Description
CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of application Ser. No. 09/747,517, filed Dec. 21, 2000 now abandoned, which is included herein in its entirety by reference.

INCORPORATION BY REFERENCE

The disclosures of Japanese Patent Application Nos. HEI 11-362058 filed on Dec. 21, 1999, and 2000-343677 filed on Nov. 10, 2000, including the specifications, drawings and abstracts are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a cooling structure for a multichip module and, more particularly, to a cooling structure for a multichip module having a plurality of electronic devices that generate different amounts of heat relative to each other.

2. Description of Related Art

In general, as a cooling structure for a multichip module, there is proposed a structure for cooling a multichip module by radiating heat from one face thereof (e.g. Japanese Patent Application Laid-Open No. HEI 11-121666). In this structure, a heat radiation body for covering a plurality of electronic devices is attached to a substrate to which the electronic devices that are different in height are mounted, with a silicon seat of high thermal conductivity being interposed among the electronic devices. Heat generated from the respective electronic devices is radiated through the heat radiation body.

The electronic devices, which are used to control electric power or the like, need to be kept below a permissible operating temperature and therefore heat generated in connection with switching operation or the like needs to be removed. Thus, it is considered important to achieve improvement of performance and size reduction in the cooling structure.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a cooling structure for a multichip module which is small in size and which demonstrates excellent cooling performance.

In order to achieve the above-stated object, according to an aspect of the invention, there is provided a cooling structure for a multichip module having a plurality of electronic devices, in which the devices generate different amount of heat relative to each other, comprising a first member which is provided on a first face of the multichip module and which transmits heat generated by the electronic devices to the outside of the module and a second member which is provided on a second face that is different from the first face, which is in contact with the electronic devices, and which has thermal conductivity.

According to the aforementioned aspect, part of the heat generated from a first electronic device which generates much heat is transmitted to a second electronic device by the second member. Thus, the electronic devices become uniform in temperature, whereby it becomes easier for the first member to transmit heat to the outside of the module. Consequently, a structure which is small in size and which provides excellent cooling effect can be obtained.

In the aforementioned aspect, electric power may be supplied to the electronic devices through the second member. This makes it possible to economize space for the member for supplying electric power and thus to achieve further size reduction.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and further objects, features and advantages of the invention will become apparent from the following description of a preferred embodiment with reference to the accompanying drawings, wherein:

FIG. 1 is a front view of the construction of a multichip module having a cooling structure according to one embodiment of the invention;

FIG. 2 is a plan view of the multichip module shown in FIG. 1 as viewed in a direction indicated by an arrow A;

FIG. 3 is a plan view of the multichip module 20 shown in FIG. 1 as viewed in a direction indicated by an arrow B;

FIG. 4 is a explanatory drawing of a heat radiation path of multichip module 20 shown in FIG. 1;

FIG. 5 is a front view of the construction of a multichip module 20 b having four electronic devices; and

FIG. 6 is a plan view of the multichip module 20 b show in FIG. 5 as viewed in a direction indicated by an arrow A.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

An embodiment of the invention will be described with reference to the drawings. FIG. 1 is a front view of the overall construction of a multichip module 20 having a cooling structure of the invention. FIG. 2 is a plan view of the multichip module 20 shown in FIG. 1 as viewed in a direction indicated by an arrow A. FIG. 3 is a plan view of the multichip module 20 shown in FIG. 1 as viewed in a direction indicated by an arrow B.

As shown in FIGS. 1 through 3, the multichip module has electronic devices 24, 26. The electronic devices 24, 26 generated different amounts of heat. The electronic devices 24, 26 are mounted to an insulate substrate 22 by means of solder 28. It is assumed herein that the generation of heat by the electronic device 24 is greater than that by the electronic device 26. The module 20 has an electrode 32 for supplying electric power to the electronic devices 24, 26, a heat leveling plate 30 that makes the electronic devices 24, 26 substantially uniform in temperature, and a heat radiation plate 40 disposed below the insulated substrate 22. Also, an insulator 34 with high the al conductivity is provided between the electrode 32 and the heat radiation plate 40.

In general, heat generated by electronic devices is varied depending on drive conditions. While the electronic device 24 includes an IGBT, a power MOS and a power transistor, the electronic device 26 includes a diode, for example.

The heat leveling plate 30 makes the temperatures of electronic devices 24, 26 substantially uniform and also supplies them with electric power from the electrode 32. Thus, an electrically conductive material of high thermal conductivity is used as a base material of the heat leveling plate 30. For example, it is possible to use aluminum, copper, molybdenum and the like.

The heat radiation plate 40 radiates heat to a cooling medium such as air and water and is thus made from a material of high thermal conductivity (e.g. a metal such as aluminum and stainless steel).

The heat radiation plate 40 may include a flow passage for the cooling medium or form a flow passage for the cooling medium in combination with another member. Fins may be provided in a portion facing the flow passage for the cooling medium to enhance cooling effect.

Next, heat radiation paths of the multichip module constructed as described above will be described. The heat radiation paths of the multichip module 20 of the embodiment include a first path wherein heat generated from the electronic devices 24, 26 flows from the heat radiation plate 40 to the cooling medium through the insulated substrate 22, a second path wherein heat generated from the electronic device 24 flows to the cooling medium through the heat leveling plate 30, the electronic device 26, the insulated substrate 22 and the heat radiation plate 40, and a third path wherein heat generated from the electronic device 24 flows to the cooling medium through the heat leveling plate 30, the electrode 32, the insulator 34 and the heat radiation plate 40. The second and third paths both include the heat leveling plate 30. That is, the heat leveling plate 30 distributes heat generated from the electronic device 24 to the electronic device 26 and the electrode 32. Accordingly, the electronic devices 24, 26 and the electrode 32 become substantially uniform in temperature. As a result, in comparison with a cooling structure provided only with the first path wherein heat generated from the electronic device 24 flows from the heat radiation plate 40 to the cooling medium through the insulated substrate 22, cooling effect of the electronic device 24 can be enhanced.

In this case, the electronic device 26 which generates less heat than the electronic device 24 is supplied with heat from the electronic device 24 by the heat leveling plate 30. Thus, the temperature of electronic device 26 becomes higher than a temperature attained by heat generation of the electronic device 26 itself. However, the permissible operating temperature of a general semiconductor device is substantially constant (e.g. approximately 150 C.) regardless of its generation of heat. Thus, as long as the temperature of the electronic device 24 is lower than the permissible operating temperature (as long as the electronic device 24 is in normal operation), the temperature of the electronic device 26 does not exceed the permissible operating temperature even if it has received heat generated by the electronic device 24 through the heat leveling plate 30.

According to the multichip module 20 described hitherto, the heat leveling plate 30 is used to make the electronic devices 24, 26 and the electrode 32 substantially uniform in temperature. Thereby it becomes possible to enhance cooling effect of the electronic device 24 in comparison with a cooling structure which does not have the heat leveling plate 30, and to reduce the size of the entire module. In addition, since the heat leveling plate 30 also serves as a member for supplying electric power to the electronic devices 24, 26 from the electrode 32, additional wire bonding does not need for supplying electric power to the electronic devices 24, 26 from the electrode. Consequently, the multichip module 20 can also be applied to small-size electronic devices which do not permit wire bonding. Also, it is possible to prevent complication of the multichip module.

It is preferable to maintain coefficient of thermal expansion of the heat leveling plate 30 and the heat radiation plate 40 in a permissible range at a steady driving state to prevent warp of the multichip module 20.

As shown in FIG. 4, heat generated by the electronic devices 24, 26 passes through the multichip module 20 along respective paths as indicated by arrows, and the heat is radiated from the heat radiation plate 40 to the outside. Accordingly, it may be difficult to level the temperature of the heat leveling plate 30 and the temperature of the heat radiation plate 40 to be substantially equal to each other. The heat radiation plate 40 having substantially the same coefficient of thermal expansion as that of the heat leveling plate 30 can prevent warp of the multichip module 20, even if there is a temperature gap between the heat leveling plate 30 and the heat radiation plate 40. It is possible to form the insulated substrate 22, instead of the heat radiation plate 40, of a material having substantially the same coefficient of thermal expansion as that of the heat leveling plate 30. It is also possible to add another member to the structure, which has the substantially the same thermal expansion as the heat leveling plate 30.

A body of the heat leveling plate 30 may be formed of a material which has thermal conductivity but which does not have electrical conductivity, for example, a ceramic material such as aluminum nitride and alumina. On a face of the heat leveling plate 30 which is in contact with the electronic devices 24, 26, a wiring pattern capable of supplying electric power from the electrode 32 may be formed of a material which has electrical conductivity.

In the multichip module 20 of the aforementioned embodiment, a member for supplying electric power to the electronic devices 24, 26 may be provided separately from the heat leveling plate 30.

In the multichip module 20 of the aforementioned embodiment, the electronic devices 24, 26 are sandwiched between the heat leveling plate 30 and the heat radiation plate 40. The heat leveling plate 30 is provided so as to advance uniformity of temperature among the electronic devices 24, 26 and the electrode 32. Therefore, the electronic devices 24, 26 may be mounted to a face of the heat leveling plate 30 which does not face the heat radiation plate 40, for example, to a lateral face or a front face of the heat leveling plate 30.

The invention may be applied to a multichip module having three or more electronic devices. For example, heat generated in a multichip module 20 b having four electronic devices 24, 24 b, 26, 26 b, as shown in FIGS. 5 and 6, can be released in the same manner as described above.

Although the embodiment of the invention has been described hitherto, the invention is not limited thereto. It goes without saying that the invention can be implemented in various forms as long as they do not depart from the spirit and scope of the invention.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US4558395 *Apr 26, 1984Dec 10, 1985Hitachi, Ltd.Cooling module for integrated circuit chips
US5021924 *Sep 14, 1989Jun 4, 1991Hitachi, Ltd.Semiconductor cooling device
US5239448 *Oct 28, 1991Aug 24, 1993International Business Machines CorporationFormulation of multichip modules
US5323292 *Oct 6, 1992Jun 21, 1994Hewlett-Packard CompanyIntegrated multi-chip module having a conformal chip/heat exchanger interface
US5345107 *Feb 20, 1992Sep 6, 1994Hitachi, Ltd.Cooling apparatus for electronic device
US5480840 *Aug 18, 1994Jan 2, 1996At&T Global Information Solutions CompanyMulti-chip module with multiple compartments
US5500555 *Apr 11, 1994Mar 19, 1996Lsi Logic CorporationMulti-layer semiconductor package substrate with thermally-conductive prepeg layer
US5751062 *Dec 13, 1995May 12, 1998Hitachi, Ltd.Cooling device of multi-chip module
US5844311 *Nov 17, 1997Dec 1, 1998Hitachi, Ltd.Multichip module with heat sink and attachment means
US5859763 *Dec 23, 1996Jan 12, 1999Electronics And Telecommunications Research InstituteMulti chip module cooling apparatus
US5930135 *Sep 30, 1998Jul 27, 1999Reliance Electric Industrial CompanyHeat sink apparatus and method for making the same
US5959352 *Dec 5, 1997Sep 28, 1999Fraunhofer-Gesellschaft Zur Forderung Der Angewandten Forschung E.V.Chip arrangement and method of producing the same
US6046410 *Aug 24, 1998Apr 4, 2000General Electric CompanyInterface structures for electronic devices
US6046498 *Jun 26, 1998Apr 4, 2000Nec CorporationDevice having a heat sink for cooling an integrated circuit
US6138348 *Mar 8, 1999Oct 31, 2000Polymer Flip Chip CorporationMethod of forming electrically conductive polymer interconnects on electrical substrates
US6144013 *Jul 1, 1999Nov 7, 2000International Business Machines CorporationLocal humidity control system for low temperature electronic module
US6366461 *Sep 29, 1999Apr 2, 2002Silicon Graphics, Inc.System and method for cooling electronic components
US6393169 *Jan 6, 1999May 21, 2002Intel CorporationMethod and apparatus for providing optical interconnection
US6469895 *Apr 23, 1997Oct 22, 2002Astec International LimitedIntegrated circuit mounting structure including a switching power supply
US6642064 *Mar 3, 1997Nov 4, 2003Altera CorporationMethod of making a high density programmable logic device in a multichip module package
US20010001989 *Jan 10, 2001May 31, 2001Smith John W.Microelectronic connections with liquid conductive elements
US20020000239 *Sep 27, 1999Jan 3, 2002Krishna G. SachdevRemoval of cured silicone adhesive for reworking electronic components
US20020003232 *Aug 22, 2001Jan 10, 2002Micron Technology, Inc.Silicon interposer with optical connections
EP0361495A2Sep 29, 1989Apr 4, 1990Hitachi, Ltd.Semiconductor package and computer using the package
EP0376478A2Nov 27, 1989Jul 4, 1990York International CorporationSystem for mounting and cooling power semiconductor devices
FR2665046A1 Title not available
JPH08195455A Title not available
JPH11121666A Title not available
WO1998012748A1Sep 18, 1996Mar 26, 1998Hitachi LtdJunction semiconductor module
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7079396Jun 14, 2004Jul 18, 2006Sun Microsystems, Inc.Memory module cooling
US7091604 *Jun 4, 2004Aug 15, 2006Cabot Microelectronics CorporationThree dimensional integrated circuits
US7211891 *Nov 26, 2004May 1, 2007Sharp Kabushiki KaishaElectronic heat pump device, laser component, optical pickup and electronic equipment
US7462934Jun 20, 2006Dec 9, 2008Microsoft CorporationIntegrated heat sink
US7589348 *Mar 14, 2006Sep 15, 2009Borealis Technical LimitedThermal tunneling gap diode with integrated spacers and vacuum seal
US7608919Nov 15, 2006Oct 27, 2009University Of Notre Dame Du LacInterconnect packaging systems
US7612443 *Sep 3, 2004Nov 3, 2009University Of Notre Dame Du LacInter-chip communication
US7932170Jun 23, 2008Apr 26, 2011Amkor Technology, Inc.Flip chip bump structure and fabrication method
US8021965Nov 15, 2006Sep 20, 2011University Of Norte Dame Du LacInter-chip communication
US8091614Nov 10, 2006Jan 10, 2012International Business Machines CorporationAir/fluid cooling system
US8390116Mar 18, 2011Mar 5, 2013Amkor Technology, Inc.Flip chip bump structure and fabrication method
US8623700Nov 15, 2006Jan 7, 2014University Of Notre Dame Du LacInter-chip communication
US8704369Feb 12, 2013Apr 22, 2014Amkor Technology, Inc.Flip chip bump structure and fabrication method
US20050110099 *Nov 26, 2004May 26, 2005Kenji ShimogishiElectronic heat pump device, laser component, optical pickup and electronic equipment
US20050269665 *Jun 4, 2004Dec 8, 2005Cabot Microelectronics Corp.Three dimensional integrated circuits
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